2 /******************************************************************************
4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
6 *****************************************************************************/
9 * Copyright (C) 2000 - 2008, Intel Corp.
10 * All rights reserved.
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13 * modification, are permitted provided that the following conditions
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21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
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24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
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45 #include <acpi/acpi.h>
48 #define _COMPONENT ACPI_HARDWARE
49 ACPI_MODULE_NAME("hwacpi")
51 /******************************************************************************
53 * FUNCTION: acpi_hw_set_mode
55 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
59 * DESCRIPTION: Transitions the system into the requested mode.
61 ******************************************************************************/
62 acpi_status
acpi_hw_set_mode(u32 mode
)
68 ACPI_FUNCTION_TRACE(hw_set_mode
);
71 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
72 * system does not support mode transition.
74 if (!acpi_gbl_FADT
.smi_command
) {
76 "No SMI_CMD in FADT, mode transition failed"));
77 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE
);
81 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
82 * in FADT: If it is zero, enabling or disabling is not supported.
83 * As old systems may have used zero for mode transition,
84 * we make sure both the numbers are zero to determine these
85 * transitions are not supported.
87 if (!acpi_gbl_FADT
.acpi_enable
&& !acpi_gbl_FADT
.acpi_disable
) {
89 "No ACPI mode transition supported in this system (enable/disable both zero)"));
90 return_ACPI_STATUS(AE_OK
);
94 case ACPI_SYS_MODE_ACPI
:
96 /* BIOS should have disabled ALL fixed and GP events */
98 status
= acpi_os_write_port(acpi_gbl_FADT
.smi_command
,
99 (u32
) acpi_gbl_FADT
.acpi_enable
, 8);
100 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
101 "Attempting to enable ACPI mode\n"));
104 case ACPI_SYS_MODE_LEGACY
:
107 * BIOS should clear all fixed status bits and restore fixed event
108 * enable bits to default
110 status
= acpi_os_write_port(acpi_gbl_FADT
.smi_command
,
111 (u32
) acpi_gbl_FADT
.acpi_disable
,
113 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
114 "Attempting to enable Legacy (non-ACPI) mode\n"));
118 return_ACPI_STATUS(AE_BAD_PARAMETER
);
121 if (ACPI_FAILURE(status
)) {
122 ACPI_EXCEPTION((AE_INFO
, status
,
123 "Could not write ACPI mode change"));
124 return_ACPI_STATUS(status
);
128 * Some hardware takes a LONG time to switch modes. Give them 3 sec to
129 * do so, but allow faster systems to proceed more quickly.
133 if (acpi_hw_get_mode() == mode
) {
134 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
135 "Mode %X successfully enabled\n",
137 return_ACPI_STATUS(AE_OK
);
143 ACPI_ERROR((AE_INFO
, "Hardware did not change modes"));
144 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE
);
147 /*******************************************************************************
149 * FUNCTION: acpi_hw_get_mode
153 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
155 * DESCRIPTION: Return current operating state of system. Determined by
156 * querying the SCI_EN bit.
158 ******************************************************************************/
160 u32
acpi_hw_get_mode(void)
165 ACPI_FUNCTION_TRACE(hw_get_mode
);
168 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
169 * system does not support mode transition.
171 if (!acpi_gbl_FADT
.smi_command
) {
172 return_UINT32(ACPI_SYS_MODE_ACPI
);
175 status
= acpi_get_register(ACPI_BITREG_SCI_ENABLE
, &value
);
176 if (ACPI_FAILURE(status
)) {
177 return_UINT32(ACPI_SYS_MODE_LEGACY
);
181 return_UINT32(ACPI_SYS_MODE_ACPI
);
183 return_UINT32(ACPI_SYS_MODE_LEGACY
);
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